How do you sort your LPs?

Here's one I haven't heard yet:  due to the size of my record cabinets (IKEA makes some great ones, I have different configurations ranging from one cube to 2 x 3 cubes that can put placed either way), I separate rock by American artists/groups versus British artists/groups, then in alphabetical order.  I have so many Beatles (group and solo) records and Beach Boys (also group and solo) records, that they merit their own separate cabinets.  

LP's?  What are those?   <g>  Actually, when I first moved to AZ and needed money, I left my stereo but brought all my albums. I sold them at a swap meet in Tucson for $1200 lump sum. Boy was that a mistake. I'd always open the album, throw the paper liner away and replace it with a plastic lined liner, and the opening was always 90 degrees to the cardboad liner, and NEVER EVER touch the grooves. 

I have over 3500 LPs at this point. I occasionally find duplicates and forgotten music. A less random arrangement would likely be better. It is fun to rediscover music though. 

I really can't imagine any practice other than basic alphabetical filing. Yes, I have a separate section for classical, and also for greatest hits collections that include multiple artists. (I collect radio station greatest hits collections. Please don't ask why.)

My LP collection is large enough that it has to be spread over two floors. So for convenience, it is filed A through Z on each floor. And in my listening room, I have a small "hot box" in the rack to file new purchases as well as current favorites, so that they don't have to be constantly refiled.

Of course, whatever works for you is what's best!

By genre then last name alphanumeric. I'm just starting to try the discog thing. Thanks uber and big greg for the tips, nice.